Electronic timer



Dec. 3, 1946.; L. F, MAYLE- 2,412,092

ELECTRONIC TIMER Filed April 9, 1945 TIME lNVENTOR F. MAYLE erovide all (N/Q51 electronic timin duration of an inte rmittently transformer is pr hereby em '1 enema? resiste a ne the

se shifting network. tial with respect to ig'ization of a 1024i cirgle cathode "c0 lender tube n0n-conducting durii idle p tential 0f the of me 35 is especizive of she p0 T 1' apparatus, fine time 01 one complete cycle 55 centrol gnd.

Sum as a Welding transformer for a time 81y equal to represented by the curve 30 of Fig. 2 has a negative value illustrated by the point 38 and the alternating current represented by the curve 3! reaches its next nodal point represented at 39, the breakcontact of relay 22 opens the circuit to the primary winding of the welding transformer 26. Again, it is seen that the contact operation coincides with a no-current instant in the welding transformer primary winding circuit. Thus, the contact points are not subject to deterioration by arcing and the welding transformer is energized for the length of time corresponding precisely to the duration of one complete alterhating current cycle.

The respective relay contacts and wil remain in the last described positions until i switch is is opened. Qbviously between the one ing or the contact and op ning of t is switch the welding transiori'nu' is not encrgized again. The opening of the switch of course, is random in time with respect to the alternating current. However, since the characteristics of the relays and are made identical, the release of these contacts following the opening of the switch it is concurrent. Thus, the circuit to the primary winding of the welding transformer is maintained in a deenergized state.

While it will be understood that the circuit specifications of the electronic timer may vary according to the design for any particular application, the following circuit specifications for a timer employed for spot welding apparatus are included by way of example only as iollows:

A. C. source lit-J volts Transformer llPrirnary, 230 volts; secondary,

60 volts with center tap Condenser l2l inicrofarad Resistor l3--10,00ll ohms Condenser i l-0.1 microiarad Tubes l5 and iii-205i Resistor l'l-560,000 ohms Resistor l856,000 ohms Tubes 2i and 24-1-1 While there has been described what, at present, is cons dered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changesand modifications may be made therein without departing from the invention, and, therefore, it is a med in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. Apparatus for controlling the energization of a load circuit comprising, a source of alternating current, a circuit closing relay having contacts operable to connect said load circuit to said source of alternating current, a circuit opening relay having contacts operable to disconnect said load circuit from said source of alternating current, and means including electronic timing apoperating winding and breal: contacts opera? to disconnect said load circuit from said source of alternating current, respective electronic gasfilled control devices to control the contact operations or" said relays, and means including a circuit connectedto said alternating current source to trigger said electronic devices successively at predetermined corresponding points of difi'erent cycles of said alternating current, whereby to effect energization of said load circuit.

, 3. Apparatus for controlling the energization of a load circuit comprising, a source of alternating current, a circuit closing relay having an operating winding and maize contacts operable to connect said load circuit to said source of alterhating current, a circuit opening relay having to disconnect said load circuit from said so alternating current, respective electronic filled. control devices to control the er of said relay windings, and a coupling connected to said alternating current source b-G trigger said electronic devices successively at predetermined corresponding points of two successive cycles of said alternating current, whereby to effect energization of said load circuit for one complete alternating current cycle.

4. Apparatus for controlling the energization of a load circuit comprising, a source of alterparatus coupled to said source of alternating current to effect successive operations of said respective relay contacts at predetermined corresponding points of different cycles of said alternating current, whereby to effect energization of said load circuit.

2. Apparatus for controlling the energization of a load circuit comprising, a source of alternating current, a circuit closing relay having make contacts operable to connect said load circuit to said source of alternating current, a circuit opening relay having break contacts operable hating current, a circuit closing relay having an operating winding and make contacts operable to connect said load circuit to said source or" alterhating current, a circuit opening relay having an operating winding and break contacts operable to disconnect said load circuit from said source of alternating current, an electronic gas-filled control device for each of said relays, each device having an. input circuit and an output circuit, the output circuits of said electronic devices being connected respectively to the windings of said relays, the winding of said circuit closing relay being connected permanently to said alternating current source and the winding of said circuit opening relay normally being disconnected from but adapted to be connected to said alternating current source by the contacts of said circuit closing relay, and a coupling circuit connected between said alternating current source and the input circuits of said electronic devices to trigger said devices successively at predetermined corresponding points of two successive cycles of said alternating current, whereby to effect energization of said load circuit for one complete alternating current cycle.

5. An electronic timer for controlling the energization of a. load circuit comprising, a source of alternating current, a. circuit closing relay having contacts operable to connect said load circuit to said source of alternating current, a

circuit opening relay having contacts operable to disconnect said load circuit from said source of alternating current, two electronic control devices each having an output circuit, means including one of said output circuits to energize said circuit closing relay, means including the other of said output circuits and the contacts of said current closing relay to energize said circuit opening relay, the contacts of said relays requiring identical operating times following the energization of the respective relays, and means connected to said alternating current source to operate said electronic devices sufliciently in advance of the actuation of said relay contacts to cause said contact actuations coincidentally with the occurrence of predetermined points of said alternating current. 6. An electronic timer for controlling the errorasiaoaa i gization of a load circuit comprising, a source of alternating current, a circuit closing relay having an operating winding and contacts operable to connect said load circuit to said source of alterhating current, a circuit opening relay having an operating winding and contacts operable to disconnect said load circuit from said source of alternating current, two electronic control devices having input circuits connected for simultaneous control and individual output circuits, the winding of said circuit closing relay being energizable under the control oi the output circuit of one of said electronic devices and the Winding of said circuit opening relay being energizable under the control of the output circuit of the other or said electronic devices and the contacts of said circuit closing relay, the contacts of said relays requiring identical actuating times following the ener gization of the respective windings, and means connected between said source of alternating current and said input circuits to operate said electronic devices at times prior to the occurrence of nodal points of said alternating currentequal toalternating current, two electronic control devices having input circuits connected for simultaneous control and output circuits connected respectively to the windings of said relays, the winding of said. circuitclosing relay being directly connected to said alternating current source and the winding of said circuit opening relay being normally disconnected from but adapted to be connected to said alternating current source by the contacts of said circuit closing relay, the contacts or said relays requiring identical actuating times following the energization of the respective windings, and means including a phase-shifting network connected between said source of alternating current and said input circuits to operate said electronic devices at times prior to the occurrence of two succesive nodal points of said alternating current equal to the actuating times of said relay'contacts, whereby to cause said contact actuations coincidentally with the occurrence of said nodal points.

8. An electronic timer for controlling the energization of a load circuit comprising, a source of alternating current, a circuit closing relay having an operating winding and make contacts operable to connect said load circuit to said source of alters nating current, a circuit opening relay having an operating winding and break contacts operable to disconnect said load circuit from said alternating current source, two electronic control devices having input circuits connected for simultaneous control and output circuits connected respectively to the windings of said-relays, the winding of said circuit closing relay being directly connected to said alternating current source and the winding of said circuit opening relay being normally disconnected from but adapted to be connected to said alternating current source by the contacts of said circuit closing relay, the contacts of said relays requiring identical operating times following the energization of the respective windings, a coupling circuit between said alternating current source and the input circuits of said electronic devices to eiiect operation of said devices, and a phase-shifting network included in said coupling circuit to operate said electronic devices sufiiciently in advance of the operation of said relay contacts to efiect said contact operations coincidentally with the occurrence of nodal points of the alternating current applied thereto.

9. Timing apparatus comprising, a source of alternating current, a circuit closing relay having normally open contacts operable to establish a connection to said source, a circuit opening relay having normally closed contacts connected in series with said normally open contacts and operable to disestablish a connection to said source, and means including electronic apparatus having input circuit electrodes coupled directly 'to said source and output circuit electrodes coupled to said source through said relays to effect successive operations of said respective relays at predetermined corresponding points of diflerent cycles of said alternating current.

LOUIS F. MAYLE. 

